Preheat oven to 400 degrees. In a medium bowl, mix sugar and flour well together. Add milk and mix with electric beater for 1 minute at medium speed, until mixture thickens slightly and lightens in color. Pour into pie shell. Bake 10 minutes, then lower temperature to 350 degrees and continue baking for 20 - 35 minutes or until filling is firm. Cool and serve with whipped cream.
